Shotcrete Services Ltd: Wellclose Square

Shotcrete Services Ltd provided supply and labour plant and materials to excavate and construct sprayed concrete enlargements within existing 2.85m ID tunnel. Enlargements ranged from 4.6m ID to 7.2mID over a length of 80m and spur tunnel for the recovery of a TBM. Works were carried out in shifts 24 hours per day using CPI silo mix concrete.

Considerable challenges were met in dealing with the pre–existing tunnel and the ground conditions encountered.

Key aspects

• Demolition and enlargement of existing tunnels
• Poor ground conditions
• Excavation with Schaef
• Civils on surface structures